5.1.8 Server Plugins

MySQL supports a plugin API that enables creation of server
components. Plugins can be loaded at server startup, or loaded and
unloaded at runtime without restarting the server. The components
supported by this interface include, but are not limited to,
storage engines, INFORMATION_SCHEMA tables,
full-text parser plugins, partitioning support, and server
extensions.

MySQL distributions include several plugins that implement server
extensions:

Semisynchronous replication plugins implement an interface to
replication capabilities that permit the master to proceed as
long as at least one slave has responded to each transaction.
See Section 17.3.8, “Semisynchronous Replication”.

The following sections describe how to install and uninstall
plugins, and how to determine at runtime which plugins are
installed and obtain formation about them. For information about
writing plugins, see Section 24.2, “The MySQL Plugin API”.